JP4387592B2 - Collision system for steering column - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steering device for a motor vehicle equipped with a steering shaft according to the preamble of claim 1.
[0002]
[Prior art]
Steering devices for motorized vehicles are often designed so that the two parts are displaced inside each other, and in a frontal collision, the steering device bends when the driver's body strikes the steering wheel. Since the impact energy is absorbed, the driver is not put at risk by the steering device. In known devices, a displaceable steering shaft tube which receives a steering shaft on the handle side is usually arranged in a housing which is fixedly secured by means of a screw connection in a predetermined position of the vehicle chassis. In this case, the screw connection is fixed in such a way that, in the event of an impact, the shaft end on the handle side can be displaced along a certain path in the axial direction with the housing console screwed together. Impact energy is absorbed accordingly by this clamping. An energy absorbing element was further arranged between the longitudinally displaced shaft portion and the vehicle chassis so that energy absorption during impact was uniform. Energy absorbing elements formed as sheet metal tabs that can be crushed became known for example from patents GB1,390,889.
[0003]
One drawback of the conventional collision system for the steering column is that, in principle, the sudden release force cannot be defined in a wide range regardless of the energy absorption capability. In addition, it was impossible to set the mode of absorption so that it could be accurately reproduced.
[0004]
[Problems to be solved by the invention]
The object of the present invention is to propose a collision system for steering column arrangement which eliminates the drawbacks of the current technology. The challenge is in particular to realize a collision system for the steering column, which can be defined reproducibly for sudden release force and energy absorption. Furthermore, the arrangement must be easy to assemble and economical production is possible.
[0005]
[Means for Solving the Problems]
This object is achieved according to the invention by an arrangement with the features of claim 1. The dependent claims define other advantageous embodiments.
[0006]
According to this invention, when the steering shaft is displaced by an impact at the time of a collision, the sudden release force is arranged to be separated from the energy absorption force.
[0007]
Therefore, in the event of a collision, the clamping and fixing must be released immediately. For this purpose, a so-called sudden release element works, and the impact energy after the clamping and fixing is released is basically applied to the energy absorbing element. As a result, the energy absorption via the defined displacement path is no longer influenced by the basically unclear clamping force, and the absorption effect can be set appropriately by providing the absorption element.
[0008]
Furthermore, in the case of the embodiment of the sudden release element, in the clamping and fixing region where a large clamping force is generated between the housing console and the fixed chassis part, the surface parts pressed against each other by the clamping are slightly inclined with respect to the sliding direction, Therefore, at a certain V-shaped angle, with only a slight displacement path, both of the V-shaped surface portions are separated from each other depending on the inclination angle, so that the original tightening is immediately reduced. In this way, only clamping impact to 2,3mm displaced when the 10 minutes added is released, further displacement Hayate not anymore be defined by undefined clamping force. A housing console for fixing the steering shaft tube is connected to the chassis via a crushing belt. This crushing belt embodiment basically defines the extent and course of energy absorption. With proper sizing of the crushing fittings, the energy absorption mode can be designed to provide optimum protection for the driver accordingly.
[0009]
In a further preferred embodiment, ridges are arranged on both sides of the sliding surface area to be pressed against each other via a short distance from each other. Thus, the sliding surface is basically formed in the slight contact area of these ridges, and when displaced, i.e. suddenly disengages, one ridge has a slight path, e.g. a few millimeters. In the event of a collision, the desired sudden release will occur. In a further, very simple and preferred embodiment of the sudden release element, the opposing clamping surfaces are stepped so that the clamping force is released after a slight path displacement in at least a partial region of the surface part to be clamped. It is formed.
[0010]
A very low-cost and space-saving steering column arrangement with a collision system for energy absorption is obtained by placing the steering shaft in a guide box, which itself is also firmly connected to the holding console. The holding console, which is firmly fixed to the vehicle chassis, for example by means of a screw connection, has a flange-like sliding surface on its side. In the event of a collision, the steering shaft is flexed with the console and tightened so that it can be displaced, for example, a few centimeters. The energy absorbing element is fixedly connected to the chassis, while where energy absorption occurs, it is connected to the steering shaft via a console. The absorbing element is preferably realized as a sheet metal member having a crushing connection fitting, and is formed in a U shape as a holding bracket , for example, and is attached between the flange of the console and the chassis. The great advantage of this embodiment is that this arrangement can be fixed to the chassis only with two fixing means, preferably with two screws. This greatly facilitates the implementation of this arrangement and allows for quick assembly, which has a positive impact on the overall cost. The starting torque of the screw here is advantageously 15 to 35 Nm. This very simple embodiment of the arrangement makes it possible to fix the entire arrangement with only two fixing screws, especially without using an independent console guide, and in the simple application also uses the special burst release element described above. At least it is available. In this case, however, the exact distinction between sudden release force and energy absorption is not very clear, and instead this arrangement can be realized at a particularly low cost.
[0011]
In the following, the invention will be described in more detail with reference to the embodiment shown in the schematic drawing.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Steering steering shaft with a shaft axis 1 is connected to the handle 2, as shown in FIG. 1, firmly to the console 6, it is placed in the guide box 3 is connected for example clamped in. The guide box 3 can further be arranged to be adjustable in height and / or longitudinal direction. The console 6 is further fixed to the vehicle chassis 18. The shafts 1 are formed so as to be displaceable inward from each other in case of a collision, so that the console 6 is also mounted so as to be displaceable in the longitudinal direction with respect to the chassis 18 in the range of up to 50 mm, for example. I have to. The console 6 is preferably formed in a U-shape and at least partially surrounds the guide box 3 to be received. Bearing guide portion 4, for example, it is fixed by a holding device 5 between the console 6. On the side of the console 6, for example, sliding surfaces 8 for receiving the longitudinal slits 20 are arranged on both sides. This slit is formed as a running slit and receives a fixing element 13, 16, 17, such as a bolt, and preferably a clamping screw 17.
[0013]
The console 6 is preferably formed by extrusion or as a sheet metal member that can be manufactured at a very low cost when formed as a bending member. In addition to the cost advantage, this has the advantage that a higher bending strength can be obtained than for example in the case of a welded structure.
[0014]
The console 6 is firmly fixed to the chassis 18 by a tightening screw 17 so that the steering shaft together with the guide box 3 is displaced longitudinally in the traveling slit when subjected to an impact. A tightening surface 22 on the console side is formed as a wedge shoe 14 inclined at a wedge angle 15 at an initial tightening position in an end region of the traveling slit 20 so that tightening is released immediately even with a slight displacement path. The The other wedge surface 22 on the screw side is similarly formed as a sliding shoe 13 with a wedge angle 15 inclined. The sliding shoe 13 is preferably formed to slide in the traveling path 20 when displaced. On the other hand, since the tightening surface is no longer 90 ° with respect to the tightening direction, the tightening force can be released immediately even with a slight displacement path. A suitable wedge angle is 2 ° to 15 °, preferably 3 ° to 8 °.
[0015]
The console 6 is screwed to the chassis 18 by, for example, a direct screw 17, and at this time, a washer 21 is disposed on the sliding shoe 13, preferably on the screw head side. 2a and 2b show a cross section of the arrangement, in which the preferred fixing method is shown on both sides of the shaft 1 in the chassis 18. For example, the wedge surface of the wedge shoe 14 can be directly incorporated into the console 6. However, when the wedge shoe is manufactured as an independent disk-shaped member and fixed to the console 6, simpler and more accurate manufacturing is possible.
[0016]
In order to clearly define the energy absorption mode, a crushing connection fitting 9 as an energy absorber preferably formed as a sheet metal member preferably having a crushing belt and a holding flap is provided. Sheet metal member surrounds the upper region of the console of the U-shaped, and is left installed fixed in the initial position to the chassis 18 by the clamping device of the console 6, it is advantageously formed as a holding bracket 7. The crushing connection fitting 9 is advantageously provided on an upper flat sheet metal member formed in the U shape of the holding bracket 7. Here, the crushing connection fitting 9 is bent as a part of the holding bracket 7 with respect to the console 6 so that the crushing connection fitting 9 can be fixed to the console, for example, by tightening or by the welding joint 11. The crushing belt with the fixed coupling is in the notch path and is adjusted by the thickness of the material of the sheet metal of the holding bracket 7, by the rigidity of the material, and by the roller width and the corresponding roller radius. In some cases, it is desirable to be able to change the characteristics of the absorptive power in the path, for example, by changing the roller width.
[0017]
The embodiment of the fully fixed arrangement, in which the holding bracket 7 with the sliding surface 12 is clamped between the flange- like sliding surface 8 of the console 6 and the chassis 18, is also provided with a special burst release element 13, 14, 22. , 26, 27, and 29 have special advantages without being used together. This arrangement is preferably low-cost finish, excellent in operation, and easy to assemble while exhibiting higher stability, especially when secured to the chassis 18 with only two screws 17. The arrangement of the present invention can be implemented without an independent console guide, which greatly simplifies the structure. This arrangement is particularly simple if, as described above, it is tightened by only two fixing screws 17 and no independent console guide is provided.
[0018]
As shown in FIG. 3a, the sliding shoe 13 is formed so that a part of the sliding shoe 13 can slide without turning in the traveling slit 20 when the console 6 is displaced. Here, the wedge surface 22 between the wedge shoe 14 and the sliding shoe 13 moves away from each other and is unfastened, but the fixing force or energy absorption in this case is determined by the crushing belt.
[0019]
The holding bracket 7 is advantageously formed as a sheet metal tab on both sides in the fixing region, which tab is between the chassis 18 and the flange-like sliding surface 8 of the console 6 and is connected to the chassis 18 by a screw connection 17. Are firmly tightened and fixed in the same manner. Therefore, when subjected to an impact, the console 6 is displaced with the wedge shoe 14 at the maximum according to the length of the traveling slit 20, and the wedge shoe 14 is thus separated from the fixed sliding shoe 13, while the holding bracket 7 is similarly fixed. The crushing coupling fitting 9 fixed to a part of the console 6 is crushed as it is. In order to join the sliding shoe 13 and the holding bracket 7 so that there is no play, a flange 16 is provided in the perforation in the holding bracket 7 so that the sliding shoe 13 is guided together, as can be seen from FIG. 2b. Is advantageous.
A top view of this arrangement is shown in FIG. 3b, where a running slit 20 is visible.
[0020]
By applying a certain surface treatment to the clamping surface 22, that is, the inclined sliding shoe surface 13 and the wedge shoe surface 14, the reproducibility of the sudden release mode can be further improved. This is possible, for example, by providing suitable irregularities on the surface and / or by coating and / or rubbing.
[0021]
The starting torque of the clamping screw is advantageously adjusted by managing the drive torque within the range of 15 to 35 Nm. FIG. 4 shows the state of the sudden release force measured for the 45 mm path on the sudden release graph. The screw connection at that time was performed with a driving torque of 25 Nm. From this figure, it can be seen that the sudden release force is greater than 9000 N, and finally descends through a long path of about 5 mm, but remains relatively large at about 6000 N and an unstable residual tightening force effect until a path of 45 mm is reached. . FIG. 5 shows an embodiment of the invention according to the arrangement of FIG. 1 under the same measurement conditions. The screw connection was similarly adjusted with a drive torque of 25 Nm. The break-through release force reaches 6000 N and immediately drops down steeply after a path of about 1 mm, and then stays at a level below 2000 N that is uniform over the entire 45 mm path by the burst release element with the inclined surface. Therefore, in the arrangement of the present invention, the energy absorption after the sudden release is performed in a short time is preferably defined by an absorption element such as a crushing coupling fitting so that it is clear, reproducible, and presettable, For example, the energy absorbing power is set to 1200 to 5500N.
[0022]
In a very suitable further way of realizing the sudden release element, as shown in FIG. 6, for example, ridges 26 and 27 are arranged between the sliding surfaces 8 and 12, which are 10 minutes in the initial position. A slight spacing from a few mm to about 3 mm is maintained. Since the raised portions 26 and 27 are basically symmetrically arranged on both sides of the sliding surface, a slight sliding surface 12 is formed at a portion where the raised portions are sandwiched and overlapped, and at the time of displacement, that is, at the time of collision. The sliding surfaces slip off from each other and release the clamping effect with a small spacing in the mm range, so that the energy absorption is completely taken over by the energy absorbing elements 7,9,11. Such a raised portion is formed, for example, in a nep shape and can be arranged on both sides of the screw fixing device 17 in the longitudinal direction of the shaft. However, depending on the requirements of tightening force, frictional force, displacement path or total dimensions, a plurality of nep-shaped ridges can be arranged side by side or back and forth, stepwise, or even on an inclined plane. Can be placed. In the above example, the sliding shoe 13 is realized as a simple shim, for example. However, it is also possible to provide these nep-shaped ridges in the region of the sliding shoe 13.
[0023]
FIG. 7 shows a further embodiment of a sudden release element that can be realized very advantageously and simply. In this embodiment, the surfaces of the sliding shoe 13 and the original wedge shoe 14 that are tightened adjacent to each other are formed in a step shape rather than a wedge shape. Here, the width of the step formed in a staircase shape defines the sudden release path. This embodiment can be realized very easily and at low cost. The various types of sudden release elements described above can also be used in combination with each other.
[Brief description of the drawings]
1 is a side view of a holding arrangement for a steering post according to the present invention.
2a is a cross-sectional view of the holding arrangement according to FIG.
FIG. 2b is a detailed view showing a cross-sectional view of the clamping and fixing device.
FIG. 3a is a detailed view showing a longitudinal section of a clamping surface arrangement with an inclined clamping surface.
3b is a top view showing details of the clamping arrangement according to FIG. 3a.
FIG. 4 is a collision force measurement diagram showing an aspect of the current technology.
FIG. 5 is a collision force measurement diagram showing an embodiment according to the present invention.
FIG. 6 is a detail view showing a longitudinal section of a further clamping surface arrangement with ridges as spacing elements between the sliding surfaces.
FIG. 7 is a detail view showing a longitudinal section of a further clamping surface arrangement with a staircase in the clamping area.

Claims (9)

A steering device for a motor vehicle having a chassis, a steering shaft having a shaft axis, a guide box (3) for guiding the steering shaft, and a console (6) connected by tightening to the guide box The console (6) has at least one sliding surface (8) along the shaft axis (1) allowing displacement relative to the chassis (18) by a displacement path (20), The device further comprises tightening means (13, 16, 17), such that the tightening force is reduced when the console (6) is displaced in the shaft axial direction (19). Furthermore, in at least a partial region of the initial position, the sudden release element (13, 14) provided with the clamping surface (22) 29, 30), and the device further includes the console (6) connected via an energy absorber (9, 10) fixed to the chassis (18), the energy absorber comprising: Including flaps that can be peeled off,
The sudden release element (13, 14, 29, 30) is arranged so that the raised portion (26, 27) on the console (6) side slides from the raised portion (26 ', 27') on the chassis side during displacement. A ridge (26, 26 ', 27, 27') arranged in pairs in the initial position in a superposed manner between the sliding surface (8) and the chassis (18) . A steering device for a motor vehicle having a chassis, a steering shaft having a shaft axis, a guide box (3) for guiding the steering shaft, and a console (6) connected by tightening to the guide box The console (6) has at least one sliding surface (8) along the shaft axis (1) allowing displacement relative to the chassis (18) by a displacement path (20), The device further comprises tightening means (13, 16, 17), such that the tightening force is reduced when the console (6) is displaced in the shaft axial direction (19). Furthermore, in at least a partial region of the initial position, the sudden release element (13, 14) provided with the clamping surface (22) 29, 30), and the device further includes the console (6) connected via an energy absorber (9, 10) fixed to the chassis (18), the energy absorber comprising: Including flaps that can be peeled off,
Apparatus wherein the burst release element (13, 14, 29, 30) comprises a stepped clamping surface (29, 22).   The device according to claim 1 or 2, wherein the energy absorber (9, 10) is a crushing coupling (9) as a flap that can be peeled off between a pair of notches (10).   The console (6) includes a means (13, 16, 17) for clamping the guide box (3), sliding surfaces (8) on both sides, and means (13, 16, 17) for clamping to the chassis (18). The apparatus according to 1 or 2.   Device according to claim 1 or 2, wherein the peelable flap comprises a sliding surface (12) arranged between the chassis (18) and the sliding surface (8) of the console (6).   3. The sliding surface (8) in the console (6) comprises a travel slot (20) for receiving a part (16, 17, 13) of the guided clamping means (1) or (2) The device described.   Device according to claim 1 or 2, wherein at least one of the clamping surfaces (22) is subjected to a surface treatment.   Device according to claim 1 or 2, wherein the console (6) is a sheet metal member.   The device according to claim 1 or 2, wherein the energy absorber (9, 10) is a tear-frame-shaped holding bracket (7) and is directly fixed to the chassis (18) by fastening means (17).

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